1. Field of the Invention
The technology relates to drill tools used for drilling into geological structures, including but not limited to potential hydrocarbon-bearing structures, and more particularly to drill tools that include an assembly that has capability for a controlled change in the direction of drilling in situ.
2. Description of the Related Art
In the field of drilling technology, it has become well known to drill a bore vertically to a predetermined or selected depth. In one aspect of drilling technology, it is known to drill the borehole at a deviated angle from vertical. This form of drilling is known as “directional” drilling, which creates boreholes that approach a horizontal deviation. This is done by drilling down in the traditional sense, and then gradually curving the direction of drilling until a substantially horizontal drilling plane is achieved to enter a region that has or is believed to have a reservoir of a desired product, often hydrocarbons such as oil and/or gas. A purpose for drilling a horizontal deviation across an oil or hydrocarbon producing region is to increase production from a reservoir, or for some other reason. To drill these multiple horizontal bores, it has been necessary to reconfigure the drill tool for each new horizontal drilling operation. Such a process is necessarily slow and laborious, and necessitates bringing the drill string to the surface for manual adjustment at regular intervals. Not only is such a procedure time consuming and prone to substantial delays, but also increases unnecessary wear on drilling equipment during the reconfiguration process, thereby substantially increasing the cost for the production of in-situ fluids. In general, the adage “time is money” applies to drilling operations where drilling rigs may be billed on a time-basis by the operator and/or owner. Therefore, there is a need for a more expedient and efficient method for horizontal drilling in-situ without necessitating that the drill tool be constantly reconfigured or brought back to the surface for adjustments.